Answer:
Amy Tan uses the rhetorical device of unifying 2+2 in the short story "Two Kinds". The story is about a young girl named Jing-mei Woo who is struggling with the expectations her mother has for her. In one scene, Jing-mei's mother is trying to teach her to play the piano, and she tells Jing-mei, "Two plus two is four. Please remember that." In this line, Jing-mei's mother is using the rhetorical device of unifying two plus two as a way of reinforcing the idea that Jing-mei needs to remember the importance of hard work, discipline, and dedication to achieving her goals. The rhetorical device works in this context because it serves to emphasize the idea that with enough effort and dedication, Jing-mei can reach her goals.